49-05-03 NAVION: Applies to Airplanes Equipped With Continental Model E185-3 Engines Having Serial Numbers 4289-D to 5110-D Inclusive, and Engines Which Have Been Equipped at Overhaul With Tri-Metal Front Main Bearing Inserts and Bronze Thrust Washers in Accordance With Continental Bulletin No. M48-7.
To be accomplished as soon as possible but not later than the first major engine overhaul.
Because of unsatisfactory service experience with Continental E185-3 engines equipped with No. 530497 Tri-Metal front main bearing inserts, and with Nos. 530494, 530495, 530544 thrust washers and 530545 dowel pins, these parts must be replaced with the original silver main thrust bearing inserts, Continental No. 40644.
Continental Service Bulletin M48-30 covers this same subject.
(Ryan Navion Field Service Bulletin No. 5 outlines the interim precautions to be taken on airplanes equipped with the unsatisfactory thrust washers until silver main thrust bearings are installed in accordance with this note.)